International Journal of Environmental & Agriculture Research (IJOEAR)
[Vol-1, Issue-4, August- 2015]
Soil Population Density, Kernel Infection and Aflatoxin Contamination in Groundnut - A Survey of North Gujarat Nakrani B. R.1, D. B. Patel2, Sharmila Gadhavi3 Regional Research Station, S.D. Agricultural University, KOTHARA-385506,Ta.Abdasa-Kachchh (Gujarat)
Abstract— About 100 groundnut pod and soil samples were collected from different locations of North Gujarat and were tested for soil population of A. flavus, percent seed infection and aflatoxin contamination. The average soil population of A. flavus of Kachchh district (4.93 x 103 cfu g-1soil) was slightly higher than Banaskantha district (4.90 x 103 cfu g-1 soil). Minimum soil population of A. flavus was recorded with the variety J-11 grown as rainfed. Moreover, it was maximum when groundnut crops were grown after groundnut whereas; minimum after pulse crops; and a little difference between the irrigated and the rainfed samples were recorded. The average of seed infection was higher in the Banaskantha district than the Kachchh. Maximum seed infection was recorded in the variety GG-20 grown as irrigated; whereas minimum in the variety J-11 cultivated in rainfed. Maximum seed infection was recorded when groundnut was grown as previous crop, while minimum when pulses were grown as previous crops. Irrigated crops showed higher seed infection as compared to the rainfed crops. None of the samples were found free from aflatoxin, but 51.00 per cent of the samples were within the safe limits. The average of Kachchh district was 14.22 ppb whereas in Banaskantha, it was 15.33 ppb .According to variety, the maximum aflatoxin (21.34 ppb) was recorded in the variety GG-2 cultivated in irrigated condition, while the variety J-11 cultivated in rainfed condition recorded minimum aflatoxin (4.55 ppb). Groundnut cultivated after groundnut recorded maximum, whereas it was minimum when pulses where grown as previous crops. Keywords— Aflatoxin, Aspergillus flavus, Groundnut, Seed infection, Soil population, Survey Aflatoxin, Aspergillus flavus, Groundnut, Seed infection, Soil population, Survey. I.
INTRODUCTION
Groundnut is grown on a large scale in almost all the tropical and subtropical countries of the world. The most important groundnut growing countries are India, China, Nigeria, Sudan and USA. Globally, it is grown on about 24.7 million hectares with a total production of 33 million tones. India occupies the first place in regard to acreage and second in production. In India, it is grown on about 6.9 million hectares with a total production of 7.3 million tonnes (FAO, 2010). Its cultivation is mostly confined to the states of Gujarat, Andhra Pradesh, Karnataka, Tamilnadu and Maharashtra. The other important states where it is grown are Madhya Pradesh, Rajasthan, Uttar Pradesh and Punjab. In Gujarat, groundnut is grown on about 1907 thousand hectares with a production of 2661 thousand tonnes and an average productivity of 1395 kg/ha. In North Gujarat, groundnut occupied an area of 159.6 thousand hectares which accounts for 8.37 % of the total groundnut grown in the state, with an average productivity of 1340 kg/ha. Area under it has been reported to increase year after year (DOA, 2009). Groundnut crop suffers from many pathogens. Many workers have detected different mould fungi and their toxin production ability in stored grains, which deteriorate the stored products (Afzal et al., 1979 and Vedahayagam et al., 1989). Among them, Aspergillus flavus is the most serious disease causing mould fungus at pre- and post- harvest/storage of crop, and is the most common species in Africa and Asia (Clinton, 1960). The toxin of A. flavus species belongs to a highly toxic group of mycotoxins known as aflatoxin. A. flavus is present throughout the groundnut growing areas in the world. The fungus survives in the soil as a saprophyte. Though it is a saprophyte, groundnut seed, seedlings, and pods are subjected to the attack of this fungus. A. flavus causes the yellow mould disease especially on ungerminated seeds and seedlings of groundnut. Infection in seedling is characterized by necrotic lesions on the emerging plumule and cotyledons. This fungus also causes the disease – Aflarot, which is associated with the presence of toxins produced by A. flavus. Clearly, scientists, farmers and development agencies must work together to find solutions to the problem. No information is available on the prevalence of different species of A. flavus across geographic location of North Gujarat. Thus, realizing the economic importance of the A. flavus and aflatoxin, present investigations were carried out.
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International Journal of Environmental & Agriculture Research (IJOEAR)
II.
[Vol-1, Issue-4, August- 2015]
MATERIALS AND METHODS
A survey was conducted during kharif 2010-11 in groundnut growing areas of Kachchh and Banaskantha districts of North Gujarat to assess the farmers’ awareness about aflatoxin contamination by A. flavus and to estimate soil population density and kernel infection in groundnut. 100 pod and soil samples were collected from different locations according to growing areas representing the Kachchh and Banaskantha districts of North Gujarat. The stratified sampling procedure was followed to collect soil and pod samples from the field at harvest/ after harvest. 2.1 Soil Sampling Soil samples were collected from 5 spots (50 g each) – one sample from each of the four corner and the fifth from the centre of a groundnut field. The samples were collected from 5-10 cm depth. All the 5 spot samples mixed to make a composite of 250 g. 2.2 Pod Sampling Mature groundnut plants / newly harvested plants at 5 spots in the field were lifted. The pods from 8-10 plants were collected and pooled to make a bulk sample of one kg. Analysis for soil population of A. flavus and kernel infection were carried out as under. 2.3 Enumeration of A. flavus population in soil sample The collected soil samples were sieved to fine powder and mixed thoroughly. From each samples, 10 g soil sample was taken in known amount of distilled sterile water to obtain 10-3 dilution factor. From this dilution, 1 ml suspension was spread on Aspergillus Flavus and Parasiticus Agar (AFPA) medium and spread uniformly with three replications, the plates were incubated at 27 ± 2oC for five days and colonies of A. flavus were counted. The population density was calculated as colony forming units (cfu) per gram of soil. 2.4 Assessment of kernel infection For seed infection, randomly collected seeds (50 seeds per sample) were imbibed in sterilized distilled water for 20-30 minutes and then surface sterilized with 0.1 % HgCl 2 for 1 minute followed by three subsequent washes of sterile distilled water. The surface sterilized seeds from each sample were plated @ 10 seeds per plate containing PDA medium amended with Rose Bengal and streptomycin sulphate. The observation for seed infection was recorded after 8 days of incubation at 27 ± 2oC. The aflatoxin content of each sample was determined by indirect competitive ELISA technique.
III.
RESULTS AND DISCUSSION
About 100 groundnut pod and soil samples were collected from different locations according to growing areas representing the Kachchh and Banaskantha districts of North Gujarat during kharif 2009 -2010 season to estimate the soil population density of A. flavus, seed infection and subsequent aflatoxin contamination. Stratified sampling procedure was followed to collect the soil and pod samples from the groundnut fields and analysis for soil population, seed infection and aflatoxin contamination were carried out as described earlier. Among the highest groundnut growing talukas of Kachchh district, Abadasa, Mandvi, Nakhatrana and Bhachau covered 28.07, 23.80, 15.71 and 13.01 % of area, respectively. However, 74.63 % of groundnut growing area of Banaskantha district was covered only by Deesa taluka. Analyzed samples were categorized in low, medium, high and very high categories for soil population and seed infection; whereas trace, moderate, high and very high for a flatoxin contamination based on their critical limits. The data of range, average and per cent distribution of samples in different categories according to taluka, variety, previous crop and irrigated/rainfed condition are presented in Table 1 to 11. 3.1 Soil Population The overall range of soil population of A. flavus of all the samples ranged between 0.33 – 9.00 (x 10 3 cfu g -1 soil) with an average of 4.92 x 10 3 cfu g -1 soil. The average of Kachchh district (4.93 x 10 3 cfu g -1 soil) was slightly higher than Banaskantha district (4.90 x 10 3 cfu g -1 soil) with the range of 0.33 – 9.00 x 10 3 cfu g -1 soil and 3.00 – 6.67 x 10 3 cfu g -1 soil, respectively. Taluka wise, the data presented in the Table 1 shows that the population of A. flavus varied highly across the taluka. Minimum average of soil populations were recorded in Rapar and Dhanera taluka (3.00 x 10 3 cfu g -1 soil) followed by Anjar (3.22 x 10 3 cfu g -1 soil), while maximum average was recorded in Vadgham (6.67 x 10 3 cfug -1 soil) followed by Palanpur (6.00 x 10 3 cfu g -1 soil) and Nakhatrana (5.92 x 10 3 cfu g -1 soil). The per cent distribution of samples revealed that 2.00, 31.00, 63.00 and 4.00 % samples fall under low, medium, high and Page | 15
International Journal of Environmental & Agriculture Research (IJOEAR)
[Vol-1, Issue-4, August- 2015]
very high categories, respectively. Very high soil population of A. flavus was recorded from Bhuj (20.00 %) followed by Mandvi (10.53 %) and Nakhatrana (7.69 %).
TABLE 1 PER CENT DISTRIBUTION, RANGE AND AVERAGE OF SOIL POPULATION(X 103 CFU G-1SOIL) OF A. FLAVUS IN DIFFERENT TALUKAS OF KACHCHH AND BANASKANTHA DISTRICTS Sr.
Taluka
No. of
No.
Area
% Area
Samples in each category (%)
Soil population (x 103 cfu g -1 soil)
Ha. Sam ple
cover ed
Low
Medium
High
Very High
(< 1)
(1-4)
(4-8)
(> 8)
Range
Average
1
Bhuj
5
4029
6.15
0.00
40.00
40.00
20.00
2.00 - 8.33
4.87
2
Mandvi
19
15600
23.80
10.53
26.32
52.63
10.53
0.33 - 9.00
4.74
3
Mundra
3
2255
3.44
0.00
66.67
33.33
0.00
2.67 - 5.67
3.89
4
Anjar
3
2225
3.39
0.00
66.67
33.33
0.00
2.00 - 4.33
3.22
5
Bhachau
10
8530
13.01
0.00
50.00
50.00
0.00
2.00 - 6.33
4.17
6
Rapar
1
1210
1.85
0.00
100.00
0.00
0.00
-
3.00
7
Nakhatrana
13
10300
15.71
0.00
15.38
76.92
7.69
3.33 - 9.00
5.92
8
Lakhapat
4
3000
4.58
0.00
75.00
25.00
0.00
2.00 - 5.33
3.42
9
Abadasa
22
18400
28.07
0.00
18.18
81.82
0.00
1.67 - 8.00
5.61
Kachchh
80
65549
100.0 0
2.50
32.50
60.00
5.00
0.33 - 9.00
4.93
10
Deesa
15
14000
74.63
0.00
20.00
80.00
0.00
3.67 - 6.67
4.84
11
Palanpur
1
625
3.33
0.00
0.00
100.00
0.00
-
6.00
12
Danta
1
500
2.67
0.00
100.00
0.00
0.00
-
4.00
13
Vadgham
1
625
3.33
0.00
0.00
100.00
0.00
-
6.67
14
Dhanera
1
1200
6.40
0.00
100.00
0.00
0.00
-
3.00
15
Dantiwada
1
1150
6.13
0.00
0.00
100.00
0.00
-
5.67
Banaskantha
20
18760
100.0 0
0.00
25.00
75.00
0.00
Total
100
84309
100.0 0
2.00
31.00
63.00
4.00
3.00 - 6.67
0.33 - 9.00
4.90
4.92
According to variety, Table 2 revealed maximum average of A. flavus soil population (5.60 x 10 3 cfu g -1 soil) in the variety GG-2 grown as rainfed with the range of 2.67 -8.33 x 10 3 cfu g -1 soil, whereas minimum value (4.03 x 10 3 cfu g -1 soil) was recorded with J-11 grown as rainfed with the range of 0.33 -8.00 x 10 3 cfu g -1 soil. 18.18 % samples of the variety GG-5 grown as irrigated were under very high categories followed by, GG -2 grown as Page | 16
International Journal of Environmental & Agriculture Research (IJOEAR)
[Vol-1, Issue-4, August- 2015]
rainfed (3.85 %) and GG-2 grown as irrigated (3.45 %); whereas only 8.70 % samples of variety J -11 grown as rainfed were under low category. Remaining all the samples were under medium to high categories.
TABLE 2 PER CENT DISTRIBUTION, RANGE AND AVERAGE OF SOIL POPULATION (X 103 CFU G-1 SOIL) OF A. FLAVUS IN DIFFERENT VARIETIES OF GROUNDNUT
Sr.
Variety
No. of Sample
No.
Soil population (x103 cfu g-1soil)
Samples in each category (%) Low (< 1)
Medium (1-4)
High (4-8)
Very High (> 8)
Range
Average
1
GG-2 Irrigated
29
0.00
34.48
62.07
3.45
2.00-8.33
5.06
2
GG-2 Rainfed
26
0.00
15.38
80.77
3.85
2.67-8.33
5.60
3
GG-5 Irrigated
11
0.00
27.27
54.55
18.18
2.00-9.00
5.27
4
J-11 Rainfed
23
8.70
43.48
47.83
0.00
0.33-8.00
4.03
5
GG-20 Irrigated
11
0.00
36.36
63.64
0.00
3.00-5.67
4.48
In case of previous crop grown, data presented in the Table 3 shows that the maximum average of A. flavus soil population (5.64 x 10 3 cfu g -1 soil) when the groundnut crops were grown after groundnut with the range of 2.67 – 9.00 x 10 3 cfu g -1 soil. However, minimum value was reported with pulse crops with the average and range of 3.97 x 10 3 cfu g -1 soil and 0.67 – 5.33 x 10 3 cfu g -1 soil, respectively. Regarding per cent distribution, 11.11 % samples were grouped under very high category when groundnut was grown as previous crop. In the low category, 10.00 % samples with pulse crops, followed by 3.45 % with cereals as previous crops. Table 4 indicates a little difference in A. flavus soil population between the irrigated (6.67 – 63.33 x 10 3 cfu g -1 soil) and rainfed samples (3.33 – 66.67 x 10 3 cfu g -1 soil). The average values for these samples were 4.98 x 10 3 cfu g -1 soil and 4.86 x 10 3 cfu g -1 soil, respectively. 5.88 and 2.04 % respectively of the irrigated and rai nfed samples were grouped under very high category. Whereas, in low category only 4.08 % samples belong to the rainfed growing condition were identified.
TABLE 3 PER CENT DISTRIBUTION, RANGE AND AVERAGE OF SOIL POPULATION (X 103 CFU G-1 SOIL) OF A. FLAVUS IN RESPONSE TO DIFFERENT PREVIOUS CROPS
Sr.
Previous Crops
No.of Sample
Samples in each category (%)
Soil population (x103 cfu g-1soil)
No. Low (< 1)
Medium (1-4)
High (4-8)
Very High (> 8)
Range
Average
1
Groundnut
36
0.00
25.00
63.89
11.11
2.67-9.00
5.64
2
Other oilseed
17
0.00
23.53
76.47
0.00
2.33-7.00
4.90
3
Cash crop
8
0.00
50.00
50.00
0.00
2.00-6.00
4.00
4
Pulses
10
10.00
30.00
60.00
0.00
0.67-5.33
3.97
5
Cereals
29
3.45
37.93
58.62
0.00
0.33-8.00
4.63
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International Journal of Environmental & Agriculture Research (IJOEAR)
[Vol-1, Issue-4, August- 2015]
TABLE 4 PER CENT DISTRIBUTION, RANGE AND AVERAGE OF SOIL POPULATION (X 103 CFU G-1SOIL) OF A. FLAVUS IN IRRIGATED AND RAINFED CONDITION
Sr.
Irrigated/ rainfed condition
No.
No. of Sample
Soil population (x103 cfu g-1soil)
Samples in each category (%)
Low (< 1)
Medium (1-4)
High (4-8)
Very High (> 8)
Range
Average
1
Irrigated
51
0.00
33.33
60.78
5.88
2.009.00
4.98
2
Rainfed
49
4.08
28.57
65.31
2.04
0.338.33
4.86
3.2 Seed infection (%) Among 100 samples which have been analyzed, the seed infection ranged between 3.33 – 66.67 % with an average of 28.47 %. The ranges for Kachchh and Banaskantha districts were 3.33 – 66.67 % and 10.00 – 63.33 % with an average of 26.96 % and 34.50 %, respectively (Table 5). Overall, 27.00, 35.00, 27.00 and 11.00 % of samples were grouped under low, medium, high and very high seed infection categories, respectively.
TABLE 5: PER CENT DISTRIBUTION, RANGE AND AVERAGE OF SEED INFECTION (%) IN GROUNDNUT SEED BY A. FLAVUS IN DIFFERENT TALUKAS OF KACHCHH AND BANASKANTHA DISTRICTS Sr.
Taluka
No. of Sample
No.
Samples in each category (%)
Seed infection (%)
< 15 %
15-30 %
30-50 %
> 50 %
Range
Average
1
Bhuj
5
20.00
60.00
20.00
0.00
6.67-36.67
24.67
2
Mandvi
19
31.58
36.84
26.32
5.26
6.67-53.33
25.26
3
Mundra
3
33.33
66.67
0.00
0.00
6.67-26.67
18.89
4
Anjar
3
33.33
33.33
33.33
0.00
6.67-33.33
20.00
5
Bhachau
10
20.00
30.00
30.00
20.00
10.00-56.67
32.67
6
Rapar
1
100.00
0.00
0.00
0.00
-
13.33
7
Nakhatrana
13
23.08
38.46
30.77
7.69
6.67-63.33
31.03
8
Lakhapat
4
75.00
25.00
0.00
0.00
3.33-23.33
10.00
9
Abadasa
22
36.36
18.18
31.82
13.64
6.67-66.67
29.70
Kachchh
80
32.50
32.50
26.25
8.75
3.33-66.67
26.96
10
Deesa
15
6.67
46.67
33.33
13.33
10.00-56.67
32.44
11
Palanpur
1
0.00
100.00
0.00
0.00
-
20.00
12
Danta
1
0.00
0.00
0.00
100.00
-
53.33
13
Vadgham
1
0.00
100.00
0.00
0.00
-
20.00
14
Dhanera
1
0.00
0.00
100.00
0.00
-
46.67
15
Dantiwada
1
0.00
0.00
0.00
100.00
-
63.33
Banaskantha
20
5.00
45.00
30.00
20.00
10.00-63.33
34.50
Total
100
27.00
35.00
27.00
11.00
3.33-66.67
28.47
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International Journal of Environmental & Agriculture Research (IJOEAR)
[Vol-1, Issue-4, August- 2015]
Taluka wise data presented in the Table 5 shows that the maximum average seed infection (63.33 %) was recorded in Dantiwada taluka, whereas minimum (10.00 %) in Lakhapat taluka. Average of seed infection of the dominant groundnut growing talukas viz., Deesa, Bhachau, Nakhatrana, Abadasa and Mandvi of both the districts were 32.44, 32.67, 31.03, 29.70 and 25.26 % falling respectively in the range of 10.00 – 56.67, 10.00 – 56.67, 6.67 – 63.33, 6.67 – 66.67 and 6.67 – 53.33 %. Out of 100 samples, 11.00, 27.00, 35.00 and 27.00 % samples fall under very high, high, medium and low categories of seed infection, respectively. The samples from Dantiwada (100.00 %), Danta (100.00 %), Bhachau (20.00 %), Abadasa (13.64 %), Deesa (13.33 %) and Mandvi (5.26 %) taluka were grouped under very high category. Maximum average seed infection (44.24 %) was recorded with variety GG -20 grown as irrigated followed by GG-5 grown as irrigated (37.58 %), whereas minimum average in the variety J -11 grown as rainfed (12.03 %)(Table 6). 36.36 % samples of the GG -20 variety grown as irrigated were grouped under very high category followed by, GG-5 grown as irrigated (18.18 %), GG -2 grown as rainfed (15.38 %) and GG-2 grown as irrigated (3.45 %). However, when the variety J-11 was grown as rainfed, 82.61 % of the samples grouped under low category.
TABLE 6 PER CENT DISTRIBUTION, RANGE AND AVERAGE OF SEED INFECTION (%) IN GROUNDNUT SEED BY A. FLAVUS IN DIFFERENT VARIETIES OF GROUNDNUT Sr.
Variety
No.of Sample
No.
Samples in each category (%) Low
Medium (15-30 %)
High
Seed infection (%)
(30-50 %)
Very High (>50 %)
Range
Average
1
GG-2 Irrigated
29
(<20.69 15 %)
55.17
20.69
3.45
6.67-53.33
25.63
2
GG-2 Rainfed
26
7.69
34.62
42.31
15.38
6.67-66.67
35.64
3
GG-5 Irrigated
11
0.00
36.36
45.45
18.18
20.0063.33
37.58
4
J-11 rainfed
23
82.61
17.39
0.00
0.00
3.33-30.00
12.03
5
GG-20 Irrigated
11
0.00
18.18
45.45
36.36
16.6763.33
44.24
According to previous crop grown (Table 7), maximum seed infect ion of 33.43 % was recorded when groundnut was grown as a previous crop with the range of 10.00 – 66.67 %, while minimum average (14.67 %) with the range of 3.33 – 26.67 % were recorded when pulses were grown as a previous crops. 16.67, 11.76 and 10.34 % samples were categorized under very high seed infection group when groundnut, other oilseed and cereal crops were grown as previous crops, respectively. When pulses were grown as a previous crop, 60.00 % of the samples grouped under low seed infection categ ory.
TABLE 7: PER CENT DISTRIBUTION, RANGE AND AVERAGE OF SEED INFECTION (%) IN GROUNDNUT SEED BY A. FLAVUS IN RESPONSE TO DIFFERENT PREVIOUS CROPS Sr.
Previous Crops
No.of Sample
No.
Samples in each category (%)
Seed infection (%)
Low (< 15 %)
Medium (15-30 %)
High (30-50 %)
Very High (> 50 %)
Range
Average
1
Groundnut
36
25.00
25.00
33.33
16.67
10.00-66.67
33.43
2
Other oilseed
17
5.88
47.06
35.29
11.76
13.33-63.33
32.75
3
Cash crop
8
12.50
50.00
37.50
0.00
6.67-46.67
29.58
4
Pulses
10
60.00
40.00
0.00
0.00
3.33-26.67
14.67
5
Cereals
29
34.48
34.48
20.69
10.34
13.33-56.67
24.25
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International Journal of Environmental & Agriculture Research (IJOEAR)
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Irrigated crops reported higher seed infection (32.22 %) as compared to the rainfed crops (24.56 %) (Table 8). 13.73 % samples of irrigated crops were recorde d under very high seed infection category. Whereas in rainfed condition 42.86 % samples were reported to be under low seed infection category.
TABLE 8 PER CENT DISTRIBUTION, RANGE AND AVERAGE OF SEED INFECTION (%) IN GROUNDNUT SEED BY A. Sr.
FLAVUS IN IRRIGATED AND RAINFED CONDITION No. of Samples in each category (%) Sample Low Medium High (30Very High (< 15 %) (15-30 %) 50 %) (>50 %)
No.
Irrigated/ rainfed condition
1
Irrigated
51
11.76
43.14
31.37
2
Rainfed
49
42.86
26.53
22.45
Seed infection (%) Range
Average
13.73
6.67-63.33
32.22
8.16
3.33-66.67
24.56
3.3 Aflatoxin contamination Among 100 samples analyzed for aflatoxin contamination, none of the samples were found free from aflatoxin but 51.00 % of the samples were within the safe l imits (Table 9).The permissible limit for aflatoxin in foods under Prevention of Food Adulteration (PFA) Act is 30 ppb (Bhat and Rao, 1990). The maximum permissible level of aflatoxin in groundnut for human consumption was first set at 30 ppb in kernels, b ut it was revised to a level of 15 ppb (Mehan et al., 1991). The average and range of all the 100 samples were 14.44 ppb and 0.81 – 36.53 ppb, respectively. The average of Kachchh district was 14.22 ppb with the range of 0.81 – 36.53 ppb; whereas in Banaskantha the average and range was 15.33 ppb and 3.25 – 28.32 ppb respectively. Aflatoxin levels were present in trace amount in 15.00 % and moderate amount in 36.00 % of the samples, but it was high in 43.00 % and very high in 6.00 % of the samples. Among the dominant groundnut growing talukas of Kachchh district, Mandvi, Abadasa and Nakhatrana taluka respectively reported 15.79, 9.09 and 7.69 % of the samples under very high category. Trace amounts of aflatoxins were recorded in samples from the Rapar (10 0.00 %), Lakhapat (75.00 %), Bhuj (20.00 %), Mandvi (15.79 %), Nakhatrana (15.38 %), Abadasa (13.64 %) and Deesa (6.67 %), (Table 9). According to variety, maximum aflatoxin content (21.34 ppb) was recorded in GG -2 grown as rainfed followed by GG-20 grown as irrigated (19.87 %), with the range of 6.04 – 36.13 ppb and 8.28 – 28.32 ppb, respectively. While the variety J-11 grown as rainfed recorded minimum average of 4.55 ppb aflatoxin with the range of 0.81 – 8.23 ppb (Table 33, Fig. 28). 19.23 and 9.09 % sa mples respectively of the varieties GG -2 grown as rainfed and GG-5 grown as irrigated reported to have very high aflatoxin content. Groundnut cultivated after groundnut recorded maximum aflatoxin content (average 17.91 ppb and range 2.12 – 36.53 ppb) followed by other oilseed crops, while minimum average of 7.72 ppb with the range of 1.07 – 17.24 ppb was recorded when pulses were grown as previous crops (Table 11). 16.67 % samples were categorized under very high aflatoxin content when groundnut was the previous crop, while trace amounts of aflatoxin were recorded in 40.00, 24.14, 12.50 and 8.33 % of the samples when pulses, cereals, cash crops, and groundnut were grown as previous crops, respectively. In irrigated crops, aflatoxin content of 15.38 ppb ( range: 3.25 – 36.53 ppb) was recorded which was higher compared to the rainfed crops with an average value of 13.46 ppb (range: 0.81 – 36.13 ppb) (Table 12). 10.20 % of sample recorded very high, while 24.49 % of samples recorded with trace amount of aflat oxin in case of rainfed crops. However, in irrigated crops most of the samples observed were under moderate to high categories of aflatoxin content. The variation in soil population, seed infection and aflatoxin content across different groundnut samples collected from different location might be due to several reasons viz., soil type, climatic condition, variety, cropping pattern and other agronomical practices. Mehan et al. (1995) noted that isolates from a vertisol field produced less aflatoxin than isolates from the red sandy loam and light sandy fields. Saleha -Nahdi (1996) reported that populations of A. flavus were higher in the pod zone than in the field soil, and it increased with maturation of the crops. They also noted that soil population of A. flavus was higher in rainfed fields than in irrigated fields and also higher in fields where groundnut had been grown in the previous year. Mehan et al. (1986) further noted that seed infection and contamination by A. flavus increased with increasing maturity of pods. However, early harvest and threshing resulted in consistently lower aflatoxin content (Rachaputi et al., 2002). Timmannavar et al. (2003) reported highest percentage infection of A. flavus in groundnut cultivars with Page | 20
International Journal of Environmental & Agriculture Research (IJOEAR)
[Vol-1, Issue-4, August- 2015]
bolder and heavy seeds as compared to smaller seed size with less test weight. They also noted that harvesting at normal date recorded lower infection of A. flavus compared to one week early or late harvesting. Rossetto et al. (2003) concluded that delayed harvesting increased A. flavus contamination and aflatoxin production in the pods. Variety J-11 has also been reported as resistance source against seed infection and aflatoxin contamination by several workers (Nayak et al., 1992; Rao et al., 1995; Upadhyay et al., 1997 and 2001; Khandar et al., 2004 and Babu et al., 2005).
TABLE 9 PER CENT DISTRIBUTION, RANGE AND AVERAGE OF AFLATOXIN CONTENT (PPB) IN GROUNDNUT SEEDS IN DIFFERENT TALUKAS OF KACHCHH AND BANASKANTHA DISTRICTS Sr.
Taluka
No. of Sample
No.
Samples in each category (%) Trace
Moderate
(<5 ppb)
Aflatoxin content (ppb)
Very high (>30 ppb)
Range
Average
(5-15 ppb)
High (15-30 ppb)
1
Bhuj
5
20.00
20.00
60.00
0.00
3.78-18.91
12.71
2
Mandvi
19
15.79
42.11
26.32
15.79
1.11-36.13
14.90
3
Mundra
3
0.00
66.67
33.33
0.00
6.04-15.95
9.74
4
Anjar
3
0.00
66.67
33.33
0.00
5.64-25.35
13.36
5
Bhachau
10
10.00
40.00
50.00
0.00
3.87-24.45
15.14
6
Rapar
1
100.00
0.00
0.00
0.00
-
3.79
7
Nakhatrana
13
15.38
23.08
53.85
7.69
2.07-36.53
14.72
8
Lakhapat
4
75.00
25.00
0.00
0.00
0.81-7.82
2.96
9
Abadasa
22
13.64
31.82
45.45
9.09
2.36-34.80
16.49
Kachchh
80
17.50
35.00
40.00
7.50
0.81-36.53
14.22
10
Deesa
15
6.67
40.00
53.33
0.00
3.25-28.32
15.21
11
Palanpur
1
0.00
100.00
0.00
0.00
-
5.61
12
Danta
1
0.00
0.00
100.00
0.00
-
20.48
13
Vadgham
1
0.00
100.00
0.00
0.00
-
8.06
14
Dhanera
1
0.00
0.00
100.00
0.00
-
19.28
15
Dantiwada
1
0.00
0.00
100.00
0.00
-
24.91
Banaskantha
20
5.00
40.00
55.00
0.00
3.25-28.32
15.33
Total
100
15.00
36.00
43.00
6.00
0.81-36.53
14.44
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International Journal of Environmental & Agriculture Research (IJOEAR)
[Vol-1, Issue-4, August- 2015]
TABLE 10 PER CENT DISTRIBUTION, RANGE AND AVERAGE OF AFLATOXIN (PPB) CONTENT IN GROUNDNUT SEEDS IN Sr.
Variety
No.of Sample
No.
DIFFERENT VARIETIES OF GROUNDNUT Samples in each category (%) Trace
Moderate
(< 5
(5-15
ppb)
ppb)
Aflatoxin content (ppb)
High (1530 ppb)
Very high (> 30 ppb)
Range
Average
1
GG-2 Irrigated
29
10.34
51.72
37.93
0.00
3.25-21.14
12.28
2
GG-2 Rainfed
26
0.00
19.23
61.54
19.23
6.04-36.13
21.34
3
GG-5 Irrigated
11
0.00
27.27
63.64
9.09
8.06-36.53
19.04
4
J-11 Rainfed
23
52.17
47.83
0.00
0.00
0.81-8.23
4.55
5
GG-20 Irrigated
11
0.00
18.18
81.82
0.00
8.28-28.32
19.87
TABLE 11 PER CENT DISTRIBUTION, RANGE AND AVERAGE OF AFLATOXIN CONTENT IN GROUNDNUT SEEDS IN Sr.
Previous Crops
No. of Sample
No.
RESPONSE TO DIFFERENT PREVIOUS CROPS Samples in each category (%) Trace
Moderate
(<5 ppb)
(5-15
High (15-30 ppb)
Very high (>30
Aflatoxin content (ppb) Range
Average
ppb) ppb) 1
Groundnut
36
8.33
27.78
47.22
16.67
2.12-36.53
17.91
2
Other oilseed
3
Cash crop
17
0.00
47.06
52.94
0.00
5.61-25.35
15.84
8
12.50
50.00
37.50
0.00
3.78-23.51
13.76
4
Pulses
10
40.00
40.00
20.00
0.00
1.07-17.24
7.72
5
Cereals
29
24.14
34.48
41.38
0.00
0.81-28.32
11.80
TABLE 12 PER CENT DISTRIBUTION, RANGE AND AVERAGE OF AFLATOXIN CONTENT IN GROUNDNUT SEEDS IN IRRIGATED AND RAINFED CONDITION Sr. No.
Irrigated/ rainfed condition
No. of Sample
Samples in each category (%) Trace
Moderate
(< 5 ppb)
(5-15
Aflatoxin content (ppb)
High (15-30 ppb)
Very high (> 30 ppb)
Range
Average
ppb) 1
Irrigated
51
5.88
39.22
52.94
1.96
3.25-36.53
15.38
2
Rainfed
49
24.49
32.65
32.65
10.20
0.81-36.13
13.46
Page | 22
International Journal of Environmental & Agriculture Research (IJOEAR)
Trace (<5 ppb)
Moderate (5-15 ppb)
[Vol-1, Issue-4, August- 2015]
High (15-30 ppb)
Very high (>30 ppb)
100
70 60
Dantiwada
Dhanera
Danta
Palanpur
Deesa
Abadasa
Lakhapat
Nakhatrana
Rapar
Bhachau
Mundra
Mandvi
Anjar
30 20 10 0
Vadgham
50 40
Bhuj
Per cent sample
90 80
Talukas FIG. 1: AFLATOXIN CONTENT (PPB) ACCORDING TO DIFFERENT TALUKA OF KACHCHH AND BANASKANTHA DISTRICTS High (15-30 ppb)
Very high (>30 ppb)
GG-2 Rainfed
47.83
52.17
18.18
9.09
19.23
19.23
GG-2 Irrigated
27.27
61.54
63.64
81.82
Moderate (5-15 ppb)
37.93
51.72
90 80 70 60 50 40 30 20 10 0
10.34
Per cent sample
Trace (<5 ppb)
GG-5 Irrigated
J-11 Rainfed
GG-20 Irrigated
Varieties
FIG. 2: AFLATOXIN LEVELS IN DIFFERENT VARIETIES OF GROUNDNUT
10
41.38
34.48
24.14
40.00
40.00
37.50
50.00
Very high (>30 ppb)
20.00
20
High (15-30 ppb)
12.50
30
16.67
27.78
40
52.94
47.22
50
8.33
Per cent sample
60
Moderate (5-15 ppb) 47.06
Trace (<5 ppb)
0 Groundnut
Other oilseed
Cash crop
Pulses
Cereals
Previous crops
FIG. 3: AFLATOXIN LEVELS ACCORDING TO PREVIOUS CROPS GROWN Page | 23
International Journal of Environmental & Agriculture Research (IJOEAR)
High (15-30 ppb)
Very high (>30 ppb)
30
10.20
24.49
40
32.65
39.22
50
32.65
60
20 1.96
10
5.88
Per cent sample
Moderate (5-15 ppb) 52.94
Trace (<5 ppb)
[Vol-1, Issue-4, August- 2015]
0 Irrigated
Rainfed Irrigated / Rainfed condition
FIG. 4: AFLATOXIN LEVELS ACCORDING TO IRRIGATED/RAINFED CONDITION REFERENCES [1] Afzal, M. R., Cheema, A. and Chaudhary, R. A. (1979). Incidence of aflatoxin producing fungi in animal feed stuff. Mycopath. 69 (3): 149-51. [2] Babu, B. N. H., Gowda, M. V. C. and Kusuma, V. P. (2005). Confectionery groundnuts resistant to seed colonization by Aspergillus flavus. Int. Arachis Newsletter 25: 10-12. [3] Clinton, R. S. S. (1960). Seed bed pathogen of groundnut in Sudan, and an attempt at control with an artificial testa. Empire J. Expt. Agric. 28: 211-222. [4] Khander, R. R., Desai, S., Dhruj, I. U., Nigam, S.N., Thakur, R. P., Waliyar, F. and Bandopadhyay, A. (2004). Mapping and management of aflatoxin contamination in groundnut in Gujarat, Andhra Pradesh and Karnataka. Information Bulletin, NATP, pp 12. [5] Mehan, V. K., McDonald, D., Ramakrishna, N. and Williams, J. H. (1986). Effects of genotype and date of harvest on infection of peanut seed by Aspergillus flavus and subsequent contamination with aflatoxin. Peanut Sci. 13 (2): 46-50. [6] Mehan, V. K., Reddy, S. V., Nahdi, S., McDonald, D. and Jayanthi, S. (1995). Aflatoxin-producing potential of various strains of Aspergillus flavus from groundnut fields in different soil types. Int. Arachis Newsletter 15: 42-43. [7] Nayak, S., Khatua, D. C. and Ghose, S. K. (1992). Screening of groundnut germplasm against Aspergillus flavus. Groundnut News. 4 (2): 3. [8] Rachaputi, N .R, Wright, G. C. and Krosch, S. (2002). Management practices to minimise pre-harvest aflatoxin contamination in Australian groundnuts. Australian J. Exp. Agric. 42 (5): 595-605. [9] Rao, M. J. V., Upadhyaya, H. D., Mehan, V. K., Nigam, S. N., McDonald, D. and Reddy, N. S. (1995). Registration of peanut germplasm ICGV 88145 and ICGV 89104 resistant to seed infection Aspergillus flavus. Crop Sci. 35: 1717. [10] Rossetto, C. A. V., Lima, T-de-M, Viegas, E-de-C, Silva, O. F and Bittencourt, A. M. (2003). Effect of lime application, harvest and drying on the sanitary quality of dry-season peanut. Pesquisa- Agropecuaria Brasileira 38 (5): 567-573. [11] Saleha Nahdi. (1996). Populations of Aspergillus flavus in field and pod-zone soil in groundnut fields. Indian Phytopath. 49 (1): 5761. [12] Timmannavar, M., Umapathy, P. N., Shekhargouda, M., Kurdikeri, M. B. and Channveerswami, A. S. (2003). Influence of harvesting stages on seed yield and quality in confectionery groundnut varieties. Seed Res. 31 (1): 13-17. [13] Upadhyaya, H. D., Nigam, S. N., Mehan, V. K. and Lenne, J. M. (1997). Aflatoxin contamination of groundnut – prospects of a genetic solution through conventional breeding. Pages 81–85 in Aflatoxin contamination problems in groundnut in Asia: proceedings of the First Working Group Meeting, 27–29 May 1996, Ministry of Agriculture and Rural Development, Hanoi, Vietnam (Mehan, V. K. and Gowda, C. L. L., (Eds.), Patancheru 502 324, Andhra Pradesh, India: International Crops Research Institute for the Semi-Arid Tropics. [14] Upadhyaya, H. D., Nigam, S. N., Mehan, V. K., Reddy, A. G. S. and Yellaiah, N. (2001). Registration of Aspergillus flavus seed infection resistant peanut germplasm ICGV 91278, ICGV 91283, and ICGV 91284. Crop Sci. 41: 559–600. [15] Vedahayagam, H. S., Indulkar, A. and Rao, S. (1989). The occurrence of Aspergillus flavus and aflatoxin in India. J. Food. Sci. Tech. 23 (2): 73–76.
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